1. Field of the Invention
The present invention relates to compounds which act as muscarinic receptor antagonists, to methods of preparing such compounds, to compositions which contain such a compound, and therapeutic uses of such compounds.
2. Discussion of the Background
Quaternary ammonium salts acting as muscarinic (M) receptor antagonist drugs are currently used in therapy to induce bronchodilation for the treatment of respiratory diseases. Examples of well known M receptor antagonists are for instance represented by ipratropium bromide and tiotropium bromide.
Some chemical classes acting as selective M3 receptor antagonist drugs have been developed for the treatment of inflammatory or obstructive airway diseases such as asthma and chronic obstructive pulmonary disease (COPD).
Quinuclidine carbamate derivatives and their use as M3 antagonists are for instance disclosed in WO 02/051841, WO 03/053966, and WO 2008/012290, which are incorporated herein by reference in their entireties. WO 2010/015324, which is incorporated herein by reference in its entirety, describes carbonate derivatives and their use as M3 antagonists.
There remains, however, a need for compounds characterized by a good activity as M3 antagonists and by an improved pulmonary stability.